Large eddy simulation of turbulent duct flows in a liquid metal mhd generator with non-uniform magnetic field

Hiromichi Kobayashi, Hiroki Shionoya, Yoshihiro Okuno

Research output: Contribution to conferencePaper

Abstract

Large-eddy simulation (LES) of the turbulent duct flows in a liquid metal magnethydrodynamic (MHD) power generator is examined to reveal the behavior of the MHD flows and the turbulent structures. The non-uniform magnetic flux density in the streamwise direction produces two eddy currents. The eddy current causes the wall-jet flows with M-shaped mean streamwise velocity profiles in the direction parallel to the external magnetic field. In contrast, the Hartmann flows with the flattened velocity profiles by the Lorentz force are produced in the direction perpendicular to the external magnetic field. In the case of the strong magnetic flux density, the turbulence structures similar to the Karman vortex sheets emerge in the downstream duct. The coherent structure model, one of the subgrid-scale models, well represents the relaminarization by the Lorentz force in comparison with the Smagorinsky model with the Van Driest’s wall function. Turbulence intensities decrease under the magnetic field, but in the wall jet flows, the streamwise one is enhanced.

Original languageEnglish
Publication statusPublished - 2011 Jan 1
Event7th International Symposium on Turbulence and Shear Flow Phenomena, TSFP 2011 - Ottawa, Canada
Duration: 2011 Jul 282011 Jul 31

Other

Other7th International Symposium on Turbulence and Shear Flow Phenomena, TSFP 2011
CountryCanada
CityOttawa
Period11/7/2811/7/31

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ASJC Scopus subject areas

  • Fluid Flow and Transfer Processes

Cite this

Kobayashi, H., Shionoya, H., & Okuno, Y. (2011). Large eddy simulation of turbulent duct flows in a liquid metal mhd generator with non-uniform magnetic field. Paper presented at 7th International Symposium on Turbulence and Shear Flow Phenomena, TSFP 2011, Ottawa, Canada.